The exemption allowed property owners to avoid paying costly fees and getting the approval of tenants to turn rent-controlled apartments into condominiums. A Washington Post series on the issue found that landlords often failed to make repairs as a way to empty the buildings.

The exemption created a "perverse incentive," said Mary M. Cheh (D-Ward 3), who joined Jim Graham (D-Ward 1) and Marion Barry (D-Ward 8) in introducing the legislation.

Graham said The Post's series spurred him to act, though Cheh said the problem had previously been brought to the council's attention and she had held a hearing on the issue last year.

"They may be a minority, but the harms are extensive," she said of the landlords who abused the exemption.

Cheh said consideration will be given only to applications filed before April 1.

"We repealed a positive incentive for people to empty buildings sometimes by very illegal methods," Graham said. He added that the legislation encourages landlords to create and maintain affordable housing by eliminating conversion fees if they do so.

"We turned it on its head," Graham said. "Instead of working against the people, the law works for the people."

Previous efforts to repeal the law failed, he said, because developers argued that they needed the exemptions to maintain affordable housing. "Of course, the bad guys took over from there," he said.

The repeal of the exemption for landlords was one of several pieces of legislation that moved through the chambers yesterday, with other votes taken on vendors and preschoolers.

Longtime vendors who sold souvenirs and food outside RFK Stadium will have preference outside the new Washington Nationals ballpark. The council unanimously approved emergency legislation that authorizes the Department of Consumer and Regulatory Affairs to establish at least 40 spots for the licensed vendors within the month.

About 20 vendors picketed outside Nationals Park last weekend during exhibition and Opening Day games to protest their initial exclusion.